Amy Finan, who heads the US-based Sabin Vaccine Institute, was on a family vacation near the Grand Canyon in September when she got a surprise call from a Rwandan number. She’d heard rumours that people there might be getting sick with the Marburg virus, a deadly Ebola-like disease with no approved vaccine or antiviral treatment – but nothing was confirmed. So she stepped out of her car to pick up the phone on the side of a motorway, and with massive trucks speeding by, discussed the growing health crisis with the office of Rwandan President Paul Kagame. It was the first of what has become a d…